South Africa's Olympic "Blade Runner" Oscar Pistorius's family will gather to meet him, a day after his release on bail pending a murder trial over the fatal shooting of his girlfriend.

"The family just want time together," a source close to them told AFP. "They haven't thought about anything except being together."

Pistorius may also hold talks with his trainer to get back on the track, despite being banned under the terms of his bail from competing outside South Africa.

"He is a professional athlete. He needs to keep his body in shape," said the source.

Pistorius was freed on bail on Friday, ahead of a trial for having shot dead his girlfriend Reeva Steenkamp.

After an emotionally charged four-day bail hearing, Pretoria magistrate Desmond Nair ruled that he was not a flight risk and did not pose a danger to society

"I come to the conclusion that the accused has made a case to be released on bail," Nair said to cries of "yes!" from Pistorius's supporters in court.

Bail was set at one million rand ($112,770) and Pistorius was also required to surrender his passport and his firearms. He will have to report twice weekly to Pretoria's Brooklyn police: between 7:00 am and 1:00 pm on Monday and Friday.

It was a first victory in what is expected to be a long legal battle with the state, which accuses Pistorius of premeditated murder. He has insisted he mistook his girlfriend for an intruder.

As the two-hour ruling was read, the 26-year-old stood in the dock weeping and quivering as his family looked on, riven with tension.

Following the magistrate's decision, Pistorius was escorted to the holding area sobbing uncontrollably, as his brother Carl hugged sister Aimee and the broader family huddled in prayer.

"We are relieved by the fact that Oscar got bail today, but at the same time, we are in mourning for Reeva Steenkamp and her family," said the athlete's uncle and family spokesman Arnold Pistorius.

"As a family, we know Oscar's version of what happened that night, and we know that it is the truth that will prevail in the coming court case."

Pastorius left the magistrate's court in a silver sports utility vehicle pursued by photographers and cameramen on motorbikes, headed to a relative's house

His arrest on February 14 shocked the world and gripped South Africa, where he became a national hero after becoming the first double amputee to compete in the Olympics.

Pistorius spent more than a week at a Pretoria police station charged with the premeditated Valentine's Day killing of Steenkamp, a model and law graduate.

If found guilty he faces a possible life sentence.

He denies the charge, saying that he shot 29-year-old Steenkamp repeatedly through a locked bathroom door having mistaken her for a burglar.

While he may have won bail however, Pistorius may not be able to avoid jail time.

While magistrate Nair harshly criticised the police work in the case, he said of Pistorius's account of events that "there are improbabilities that need to be explored."

And just hours before the magistrate's decision, Pistorius's lawyer Barry Roux appeared to concede that the star sprinter could be convicted on a lesser charge of homicide.

"We can never ever say that he acted in self-defence," defence Barry Roux told the court "He is exposed to be convicted of culpable homicide."

That charge entails negligence rather than murderous intent can carry a sentence of up to 15 years in prison.

The bail proceedings offered more than a glimpse of what is to come, with so many details about Steenkamp's last hours that it sometimes appeared to be a trial in miniature.

Chief prosecutor Gerrie Nel summed up the state's case.

"He fired four shots, not one. He meant to kill. On his own version, he's bound to be convicted."

Pistorius "must realise that a long term of imprisonment is almost guaranteed," he added.

But the prosecution will be worried that its evidence was so easily picked apart by the defence.

Serious doubt was cast on the work of Hilton Botha, the detective who investigated the crime scene.

Under oath, Botha admitted he may have contaminated the crime scene and appeared to undermine a neighbour's accounts of an argument between Pistorius and Steenkamp before she died.

He has since been taken off the case after it emerged he faces seven attempted murder charges for having opened fire on a minibus in 2011.

But his errors could be significant in a case where the only eyewitnesses are the accused and the deceased.

The country's most senior detective, Lieutenant General Vineshkumar Moonoo, has been brought in to lead the case and the prosecution will now have to regroup and try to put the case back on track.

Pistorius is due back in court on June 4 for a procedural preliminary appearance.